952 CONTEIBUTIONS FEOM THE NATIONAL HEEBAEIUM. 



Plants relatively small, subglobose. 



Flowers yellow 7. E. polycephalus. 



Flowers pink 8. E. horizonthalonius. 



1. Echinocactus grusonii Hildemann, Monatsschr. Kakteenk. 1: 4. 1891. 

 San Luis Potosi and Hidalgo. 



Plants single, depressed-globose, 20 to 130 cm. high or more, often 40 to 80 

 cm. in diameter, light green ; ribs 21 to 37, rather thin and high ; spines when 

 young golden yellow, becoming pale and nearly white, in age dirty brown ; 

 radial spines 8 to 10, subulate, 3 cm. long ; central spines usually 4, up to 5 cm. 

 long; flowers 4 to 6 cm. long, 5 cm. broad at top, the segments never widely 

 spreading; flower tube 3 cm. broad, covered with lanceolate long-acuminate 

 scales ; outer perianth segments long-acuminate, brownish on the outside, yel- 

 lowish within ; inner perianth segments cadmium-yellow, erect, narrowly 

 lanceolate, acuminate ; ovary spherical, bearing acuminate scales with an 

 abundance of wool in their axils ; fruit oblong to spherical, 12 to 20 mm. long, 

 thin-walled, covered with white wool or becoming naked below ; seeds smooth, 

 dark chestnut-brown, shining, 1.5 mm. long. 



Echinocactus corynacanthus Scheidw. and E. galcottii Scheidw. (AUg. Gar- 

 tenz. 9: 50. 1841) may belong here. 



2. Echinocactus ingens Zucc. ; Pfeiff. Enuni. Cact. 54. 1837. 

 Hidalgo and elsewhere in central Mexico. 



Globular to short-oblong, 150 cm. high, 125 cm. in diameter (but reported bj 

 Karwinsky to be 5 to 6 feet in diameter), glaucescent, somewhat purplish, very 

 woolly at the top; ribs numerous, tuberculate; areoles large, distant, 2.5 to 3 

 cm. apart, bearing copious yellow wool ; spines brown, straight, rigid, 2 to 3 cm. 

 long ; radial spines 8 ; central spine 1 ; perianth 2 cm. long, 3 cm. broad ; inner 

 perianth segments linear-oblong, j^ellow, entire, obtuse; fruit ovoid, 3 cm. long, 

 copiously covered by wool, coming from the axils of small scales; seeds large, 

 black, shining, reniform. 



3. Echinocactus visnaga Hook, in Curtis's Bot. Mag. 77: pi. ^559. 1851. 

 San Luis Potosi. 



Very large, 2 to 3 meters high, 70 to 100 cm. in diameter, glaucous-green, the 

 summit covered with a mass of tawny wool ; ribs 15 to 40, somewhat undulate 

 but hardly tubercled, acute ; areoles large, approximate and sometimes almost 

 touching one another ; spines 4, stout, subulate, all radial, the upper one erect, 

 5 cm. long, the 3 lower spreading, pale brown ; flowers yellow, 7 to 8 cm. broad 

 when fully expanded ; inner perianth segments numerous, oblojig, spatulate, 

 acute, serrate, 3.5 long ; ovary elongate, 8 to 10 cm. long, crowned by the per- 

 sistent perianth, densely lanate ; scales on upper part of ovary, at least, narrow, 

 subpungent. 



4. Echinocactus grandis Rose, Contr. U. S. Nat. Herb. 10: 126. 1906. 

 Puebla, the type from Tehuacan. 



Simple, cylindric, 1 to 2 meters high, 60 to 100 cm. in diameter, dull green 

 and. when young, with broad horizontal bands, very woolly at the crown ; 

 ribs on young plants as few as 8, broad, high, and more or less undulate, 

 but in old plants very numerous and rather thin ; areoles remote on young 

 plants, confluent in old flowering plants ; spines stout, subulate, distinctly 

 banded, especially the stouter ones, at first yellowish but soon reddish brown ; 

 radial spines usually 5 or 6, 3 to 4 cm. long, central spine solitary, 4 to 

 5 cm. long, straight ; flowers numerous, yellow, 4 to 5 cm. long ; scales on the 

 ovary linear, their axils bearing an abundance of wool covering the ovary 



I 



